Combination band and shoe brake



T. P. CHASE ET AL COMBINATION BAND AND SHOE BRAKE Feb. 23, 1932.

Filed Feb. 23, 1929 3 Sheets-Sheet a wwww j N Feb. 23, 1932. 1-. P. CHASE ET AL COMBINATION BAND AND SHOE BRAKE Filed Feb. 25, 1929 3 Sheets-Sheet 2 Feb. 23, 1932.

T. P. CHASE ET AL COMBINATION BAND AND SHQE BRAKE Filed Feb. 23. 1929 3 Sheets-Sheet Patented Feh. 23, 1932 SIGNORS GAN, A CORPORATION OF DELAWARE COMBINATION BAND AND SHOE BRAKE Application This invention relates to lorakes, and has been designed as an improved brali'e for use on vehicles.

An object of the invention is to provide a hralce which shall lie effective to check drum rotation in both directions, and one which shall require only moderate pedal pressure.

he a further object, the invention aims to combine a flexible band type of brake with a rigid shoe type in such a way as to secure an exceedingly efi'cctivc brake action.

As a still further and very important object, the invention aims to make possible an eilicicnt lu'alce at a very low cost.

Other objects and advantages will be up prccialcd from the following description.

in the drawings:

Figure l is a section through. 1: brake drum showingthe novel brake means in elevation;

29 Figure is a section on line 2--2 of F igure 1;

Figure 3 is a section on line 3-3 of Fig ure 1;

Figure 4 is a section on line 4- l of Fig 2.5 are 1;

Figure 5 is a section. on line 5-5 of Fig are 1;

Figure 6 is a section on line 6-6 of Fig UIG 1; no Figure 7 is a section on line of Figure 1,

Figure 8 is a. section through the drum showing a modified form of brake means in elevation;

Figure 9 is "are 8;

Figure 10 1s a section on line 10-l0 of Fig ure 8;

Figure 11 shows in w form of mounting for means;

Figure 12 is a section corresponding to that of Figure 1 showing in elevation still another form of brake means;

Figure 13 is a section on line 13--l3 of Figure 12;

Figure 14 is a Figure 12.

Referring by reference characters to the drawings, an first to Figures 1 to 7 ina section on line 9-9 of F igelevation a modified a part of the brake section on line 14--l4 of drum flange, and choc filed February 23, 1929. Serial No. 342,207.

elusive, numeral 15 represents the head and 17 the flange of a brake drum adapted to be mounted on a, vehicle thereto in any suitable Wa and to which ring is attached a-plate 23, this being the plate commonly called the backing plate. This backing plate closes the open side of the drum, an serves as an anchor for the brake means which is k the rotation of the drum and the wheel to which it is secured. It is through this backing plate that the rotating shaft for applying the brake is extended.

The brake means for engaging the drum is novel. It con'iprises a band memher 25, more or less flexible, and extending' continuously around the drum from a po] tion adjacent one side of the actuating cam to a position near the other side of the cam. This hand, in the form of the invention illustrated in Figures 1 to 7, is of channel shape in section. The depth nel flanges 26 increases from one end of the band to a position near the other end of the band, as shown in the drawings. lining 27 is secured by rivets, as usual, to the web of the channel. This lining 27 extends from the free end of the band, as at a, to a point 6 spaced from the other end. At the free end a, a pin 29 passes through the channel flanges. T is pin also passes through a pair of links 31 and a. spacer 33 within the channel. The links extend radially inward, and are bent into contact as at 35. These inner ends are slotted to engage a pin 37 mounted in the hacking plate. spring 39 connects pin 29 with pin 37 to hold the free end of the hand off the drum, when the brake is released, the clearance being determined by the engagement of pin 37 in the slotted ends of the links 31. djustment of this clearance may he made by pin 37 eccentric relative to its axis of in the hacking plate, The axial position of the 41 and a nut 43.

s best shown in Figure 45 secured as at 47 to the as shown 3, there isa guide backing plate, the

to engage the i of the chanfor a rigid 0 bolt passes 64-. The shoe members 53 may ets 69. Rotatable in the plate may be operated by a ing movement of element 103 in any In the operation of braking it may be as-.

55 wrapping is effective guide having a U-shaped end. 49 engaging over one of the band flanges. This prevents transverse movement of the brake means.

Figure :5 illustrates the pivotal mounting shoe 51. This shoe is made of two plates 53. At the pivot flanged spacer 55 is provided with abushing 57 and mounted on a pivot bolt 59. A cotter pin 01 is used to retain the assembly in position. This pivot through the backing plate 23 and is secured by a nut 63. The brake. shoe members 53 extend within the flanges of the band at its end and extend beyond the end thereof in the form of slotted extremities be received in openings in the'band web, and be secured to the band in any suitable wa A lining 27' is secured at the end of the band, extending from the extreme end to a point designated 29 bv c.

Figure 4; shows an adjustable stop to determine the clearance at the shoe end of the brake means. This may comprise an angular plate 67 secured to the backing plate by riv- 07 and the backing plate 23 is a pin 71 held by a washer 72 surroundin the pin and engaging one side of the has 'ing plate, and an adjustable nut 73 on the outer side. The pin is provided 30 with an eccentric 75 designed to engage an abutment 77 held bv fastening means 7 9 to the shoe plates 53. eleasing springs 81, 8 hold. the brake means oil the drum and in contact with their abutments. The brake cam 83 having a cambushing 87 journals this shaft in a swinging link 89 pivoted at 91 to the backing plate, there being a spacing member 93 and a nut 95 for the pivot pin 91. It is shaft 85. A

40 upon this pin that the adjacent ends of springs 81 and 81' are mounted. The cam acts upon rockers 97 pivoted bet-ween the flanges 0 the band and the plates 53 of the shoe. Pins 99 carried by the rockers limit the swinging movement of the rockers about their pivot by the slots at engagement with the walls of of the band.

the end of the shoe and at the end The opening 101 in the backing plate is 0 such dimensions as to provide for the swinglink 89. Rotation of the camshaft may be efiected by an element 103 secured to the camshaft outside the. backing plate, and a lever arm, shown in section at 105, which may be adjustably secured to the desired manner.

sumed that the drum is rotating in a counter-clockwisedireotion when the vehicle moves forward. When, now, the cam is rotated it tends to expand the end of theband and of the.

shoe into contact with the drum. The action of the cam at the free end of the band is supplementedfby the rotary elfect of the drum tending to carry the band with it. This throughout the major f backing plate ter-clockwise direction, the shoe actually does I swing counter-clockwise away and into contact with its stop 67. This rigi shoe, therefore, acts as an anchor for the band, the effective force of the cam functionin solely to apply the band to the drum, the ban being, as will be readily understood, substantially full wrapping. To check the rotation of the drum in its reverse direction, the floatin g cam operates to expand both the shoe and the cam into drum contact. In this case, the band is less eflicient since the drum tends to unwrap it from drum contact. The cam pressure on the shoe, however, is supplemented by a self-actuatin force caused b the action of the rotating drum upon the s oe. In this case, the cam may swing bodily to some extent, there being a clockwise rotation of link from the drum 89 to accommodate the self-actuation of the tapering in its radial dimension as before.

A shoe 107 is secured to the band at its thickor end by fastening means 108. This shoe is pivoted to the backing plate at 109. At the free end of the band is a radial extension 110 to which is secured a flexible strip 111 suitably anchored at a position near the center of the drum to a plate 113 secured to the by fastening means 115. This 111 determines by its length the resilient strip of the band. It

clearance at the free end yields-when the brake is applied and b its resiliency restores the free end of the bra e to its initial position after brake action. It

also serves to prevent any possible grabbing of the brake by severe contact at the free end Plate 117 carries an eccentric stop 119, and a releasing spring 121, connected to the shoe 107 and to plate 113, holds the shoe end of thi brake means in released position. The brak may be applied by a toggle. This toggl comprises, first, a pair of links 123 pivoted t the end of the band and to a link 125. It als includes an adjustable link between the lin 125 and the shoe. This adjustable link con prises a member 129 pivoted on the pin 12 till ' one end the emons which joins the links 123 and the link 125. It nlso includes a member 131 pivoted to the shoe. The members 129 and 131 have thread rd stems engaged by a rotatable member 133. member 133 has a series of openings 135 which may he engaged by a tool pro ected through an opening 136 in the backing plate. This latter opening may be covered by a cover plate 137.

In the illustration the brake is shown as used on a front Wheel knuckle 139 provided with a spindle 141 for a front wheel. The brake shoe 107 is shown in Figure 9 as composed of two angular plates 143. In this case the operation is substantially the same as in the :form already described. C0nnter-clockwise rotation is checked by a full wrapping band extending to a point adjacent the heel of shoe 107. The shoe is then oil the drum, the rotating drum carrying it to its stop 119. The shoe then serves as an anchor for the full wrapping band. The reverse motion is checked by the shoe and hand, both being expanded against the drum by the toggle. In this case, the shoe is a self-actuating force supplementing the pedal pressure. The band tends to unwrap this unwrapping; force acting against the erm 125 carried by a suitable shaft. not shown, journaled in the backing plate at 128.

Figure 11 shows .a minor modification of the brake means. In this form an articulated link 145 is pivoted to a shoe 107' and to the backing late. In other respects the structure is so stantinlly the same. The function oi the nrticnlated link 14-5 is to insure con-- formity with the drum.

Figures 12, 13 and 14 show still another form, this form being designed to obtain an even greater, more complete full wrapping notion. in this "form the drum 151 is engaged by a band 153 varying in Width as before. his band is provided with a lining 155. At band is inturned as at 157 and secured thereto as a. resilient blade 159 corresponding to the blade 111 of the form shown by Figm'e 8. This blade is fixedly secured at its inner end to a plate 16.1 held by fastening means 163. band, the thicker end, is secured a rigid shoe 1 by fastening means 167. It is noted, however, in this case that the fastening means is nt the toe end of the shoe only, the hand being not positively connected with the shoe at its heel. he shoe is pivoted at 169 to a plate 1'11 fastened as at 173 to the backing plate. Near the heel of the shoe is a recess containing a spring 175 in abutment with the bottom of the recess. A bolt 1?? has its head in a countersink 179 on the onte face of the band, and passes through the shoe we seen and is encircled by spring 1%. A not 181, together with a washer, forms the abutment tor the other end of the spring. To

At the other end of the serve as a stop for the shoe, a plate 183 is secured to the backing plate. To this plate 183 is pivoted e two-arm lever 185. (his arm of the lever is designed to engage the the otl cure the desired shoe clearance. This positioning means comprises a threaded stud 188 held in adjusted position by a nut 187. A. spring 191 connects the shoe 165 with plate 161 and shoe against its is released, and.

tion. The brake may be applied by a toggle comprising links 193 and 195. The adjacent ends of these links are pivoted to a link 197, the latter ivoted at its other end to an arm 199 carried by an operating shaft, not shown, extending through the backin Links 193 and 195 are pivotcd the band and to the shoe by pivot means 203. The toggle link 195 may have its part pivoted to the shoe in. the form of a hollow member 205. Rotatably supported in this hollow member is a tubular stem 207, this stem bcion: in threaded engagement with that partof link 195 which is pivoted to link 193. The member 207 constitutes an adjusting memher, and for the purpose of adjustment its head flange has a plurality of o )enings 209 which may be engaged by a suitable tool projecting through an opening in the backing plate 211 normally closed by a cover 213. In this form of the invention the band isself wrapping all the Way to the toe of the shoe, the spring ,175 yielding to permit the band to so operate. When the brake is released the spring 175 functions to hold the band against the heel of the shoe. In stopping reverse to the end of shoe, and ier arm 1s variably positioned to seplate at 201 a action here, as before, the hand tends to unwrap, and the shoe becomes self-actuating.

Ve claim:

1. In combination, a drum, brake means to engage the drum comprising a band designed to be substantially full wrapping for one direction of drum rotation, and a shoe having a fixed pivot and attached at one end of said band designed to be self-actuating to check t 1e reverse direction of drum rotation.

2. In combination, a drum, 8. self-wrapping band, a rigid shoe secured to one end of said band to constitute pended lllltO drum contact, means operably engaging said band and shoe to apply the brake.

3. In combination, a drum, a flexible band, a rigid shoe secured adjacent one end of the band, pivot means for rotatahly mounting said shoe, means operably engaging the adjacent ends of said shoe and said band to apply the brake whereby a full wrapping band checks the drum rotation in one direction and a selfectnating shoe serves to check to tation in the opposite direction.

1. The invention defined by claim 3, said band being the shoe end. i 5. In combination, a drum. a flexible band, a rigid shoe having a fixed pivot, a stop to at times limit rotation of said shoe about its pivot, said shoe being secured at one end of said band, actuating int-ans operably associated with the adjacent ends of the band and shoe whereby drum rotation in one direction is checked substantially wholly by the wra ping band, and in the other direction by the 10int action of an unwrapping band and self-actuating shoe.

6. The invention set forth in claim 5, said band being of channel shape in cross section.

7. The invention as; set forth in claim 5, said actuating means comprising a floating cam, and means carried by said shoe and band engaging said cam.

8. In combination, a rotatable drum, a fixed plate, asubstantially full wrapping band in said drum, a rigid shoe pivot-ally anchored to said fixed plate and peripherally attached to an end of said band, a stop to limit the rotation of said shoe, actuating means extending through said fixed plate and operably associated with the adjacent ends of said band and shoe whereby drum rotation in one direction is checked by the wrapping band, the shoe providing the band anchor, and whereby the self-actuating shoe together with the band may serve to check reverse drum rotation.

9. The invention defined by claim 8, said actuating means being circumferentially movable.

10 in combination, a drum, brake means to on age the drum and check' its rotation, said rake means comprising a Wrapping band and a rigid shoe secured to one end 0 said band, said shoe being pivotally mounted, a stop to limit the rotation of said shoe, operating means associated with the adjacent ends of the shoe and band whereby rotation of the drum is checked by the wrapping band, the shoe rotating away from the drum under the influence oi: said drum into contact with said stop, and serving as an anchor for said band, and whereby opposite rotation of said drum may be checked by manual pressure applied to said shoe and self-actuation caused by the rotating drum, the band being simultaneously applied to the drum against the unwrapping force cause by drum rotation.

In testimony whereof we afiix our signatures.

THERON P. CHASE. WILLIAM S, LEE.

of increasing rigidity toward aseaoe-i 

